1. Field of the Invention
The present invention relates to a door lock for a motor vehicle door, which is formed integrally with a detachable door hinge having two hinge halves attached to respective two parts of a door assembly, a door and a door pillar, and connected with a hinge pin for rotation relative to each other with the hinge pin being received in one of the two hinge halves with a running fit and being connected with another of the two hinge halves for joint rotation therewith, with the door lock including a plurality of braking and locking bodies which are formed as rolling bodies, a support for supporting the bracking and locking bodies, the support being arranged concentrically with respect to a hinge axis and being connected with the hinge pin for joint rotation therewith, a plurality of axles extending transverse to the hinge pin axis for supporting the braking and locking bodies in the support, a locking device having a plurality of detent markings corresponding to the plurality of braking and locking bodies, the locking device having an at least partially curved running track concentrically arranged with respect to the hinge pin axis and fixedly connected with the one of the two hinge halves, the braking and locking bodies cooperating with the locking device for retaining the motor vehicle door in a predetermined position, and a spring element supported against the hinge pin and at least partially congruent with the locking device for biasing the support toward the locking device.
2. Description of the Prior Art
In door locks of the type described above, there is provided at least one braking and locking body which is formed as a rolling body rotatably supported on an axle extending transverse to the hinge pin axis. The braking and locking body is biased by a loading spring, which is supported at the free end of the hinge pin, into indentations which define detent markings of a running track. The indentations are provided on the end surface of the at least partially curved running track formed on a collar concentrically arranged with respect to the hinge pin axis. Generally, the braking and locking bodies are formed as conical rollers and are supported on a metal support engageable by the loading spring which simultaneously connects the support with the hinge pin for their joint rotation. In this type of a door lock, also the loading spring is connected with the hinge pin by a metallic support which is form-lockingly connected with support for the braking and locking bodies by end face toothing.
Such construction of the door lock permits, advantageously, to reduce the door lock dimensions which insures that less mounting space is needed for a hinge-lock assembly and insures a cost-effective manufacturing of the assembly. However, a drawback of this construction consists in that the loading spring which is associated with the support for the braking and locking bodies, is formed of a plate spring pack that applies a biasing force to a central region of the support which surrounds the hinge pin and that has a comparatively large weight. A relatively noiseless operation of such a door lock is possible only when the engageable with each other structural components are formed with minimal tolerances which results in relatively high manufacturing costs. Also, in case of unfavorable tolerance pairs, predetermined locking positions of the door cannot be adequately retained, and/or an insufficient braking and locking force is applied to the door.
Accordingly, an object of the present invention is to provide a door lock of the above-described type in which a predetermined position of the door is reliably retained.
Another object of the present invention is to provide a door lock of the above-described type which can be produced with the smallest possible manufacturing costs.
A further object of the present invention is to provide a door lock of the above-described type a noiseless operation of which is achieved independent of the tolerances.